Composite wood product



Aug. 3, 1948. c. ROMAN 2,6,304

COMPOSITE WOOD PRODUCT Filed Feb. 23, 1944 Gave/W:

a ZZGSEDMQK 7 Paientcd Aug. 3, 1948 UNITED STATES PATENT OFFICECOMPOSITE WOOD PRODUGI Charles Roman, Miami, Fla.

Application February 23, 1944, Serial No. 523,610

(Cl. Mil-17.3)

The present invention has a two-fold object. The first is to provide anartificial wood shape of such characteristics as to yield a much moreartistic and pleasin article than has heretofore been available fromwaste material and the other is to make it possible to usefully employ amaterial which has heretofore represented a very great economic waste.

The importance and advantages of the invention will be best appreciatedby an understanding of the conditions which prevail at lumber mills andespecially at the mills of the Pacific Northwest. In these areas greatlogs of red wood, spruce, fir, ponderosa pine and other varieties areconverted into vast quantities of lumber in day by day operations whichleave enormous quantities of waste wood to be disposed of. Thiscomprises the slabs from the log with the adhering bark, pieces of smalllimbs, twigs, leaves, etc. The mills dispose of as much of this wastematerial as possible by using it for fuel but there still remainhundreds of thousands of tons for which no susbtantial use hasheretofore been devised. In the use of this waste wood for fuel it isusually broken into relatively small pieces by being passed through ahog-mill and the resultant product is commonly known throughout theindustry as hog fuel.

In carrying out the present invention I subject this hog fuel to ahammer-like comminuting action, which not only reduces the particles asto size but which flattens the chips of appreciable size and squeezesthem to harden their fiat surfaces and to cause whisker-like fibres toprotrude along their edges. These fibres interlock in a way hereinafterset forth.

The product of the hammer mill consisting of particles ranging fromgranular wood meal to good sized chips is then molded into an artificiala pounding and rubbing action which iscontinued as the particles passover an arcuate grate like bottom, and through which the particles fallwhen sufficiently reduced in size.

The mill constitutes no part oi the invention. I employ conventionalmills which have been available in the open market for years. In all ofthese mills the ultimate nature and fineness of .twigs, bark and thelike. In other words, no attempt is made to sort the hog wood content.The most economical, and consequently the preferred way, is to take thewaste product as it comes and subject it to the action of a hammer millor its equivalent. However, it so happens that this way which is themost economical is also the way which yields the most beautiful eflectsin the finished product. This is due to the fact that when the entirewaste is used many difierent colors and shades are present which give anattractive and artistic effect in the finished product. For example, thepieces of bark are usually much darker than the other particles as wellas being more absorbent of paints, stains, etc. Thus, mottled and mosaiceil'ects appear in the finished product, as presently set forth.

This product from the hammer mill comprising, as stated, particlesranging from wood meal up to good sized chips is mixed with an adhesive,waterproof binder in a heterogeneous mass and to the consistency of.merely a damp and not a,

wood shape by the use of a binder and the appli- 4o slushy mass. It isagitated well to eflect thorous'h cation of pressure in the presence ofeither heat or cold.

Both hog mills and hammer mills are well known to the industry. The hogmill diflers from the hammer mill in that its striking elements havechisel-like edges which act to break the pieces of wood against abreaking plate. The striking elements are pivoted to a revolving carrierand they move over a grate like bottom through which the comminutedparticles fall so when theyhave been sufiiciently reduced in size. Thehammer mill, upon the other hand, has its like pivoted striking elementsrounded upon their ends so that they do out but trap the particlesmixing of the whole and is then subjected to molding pressure in anydesired type of press or machine. In this heterogeneous mass the smallsticks, chips, etc., extend at a great multiplicity of angles, bothlongitudinally and laterally of the mass, with the result that astructure of great strength is provided. While I have used the termshape in describing this artificial wood product to'indicate that it isof use in forming any shape of artificial wood article, such as columns,beams, molding and the like, one of its greatest fields of usefulness isin the manufacture of artificial board. In this field it yields markedfeatures of superiority over known products from between themselves anda fixed serrated wall with 6 the standpoint of economy, strength,artistic appearance and sound-proofing capability. It is cheap becauseit is made of a wasteproduct'already existent in large quantities and adrug on the market; it is'strong in that it is not made by felting afterthe manner of many wall boards. Its fibres do not all extend in the samedirection as in the case of felted products. Upon the contrary, theyextend in every conceivable direction and internally brace the boardagainst lateral bending, so that it will not easily break. Every littlestick and chip is an internal brace, adding strength to the whole.Further, the whisker like fibers produced along the edges or the chipsof considerable size interlock with the fibres of other particles to tiethe whole firmly together. It has superior sound-profing qualitiesbecause the heterogeneous disposition of the particles, together withtheir size leaves interstices and voids which, while individually verysmall, complementally provide a mass of sound-proofing or entrappingcavities to absorb sound waves. Finally, the artistic surface appearanceof the finished product is much superior to products made from particlesof uniform size and color. Much of the wall board on the market isfiatand drab in appearance and some of it is much like blotting paper inits capacity to absorb paint and other covering compositions. My productdifi'ers from products of the nature described in that it provides ahard waterproof surface of a distinctly ornamental nature.

One form of product which I have manufactured by the method of thisinvention has its particles ranging from the granular wood meal up tochips of about three-quarters of an inch in length to aboutthree-eighths of an inch in width. Thus, the finished surface presents anumber of flat hard surfaces represented by the pounded faces of thesechips and disposed at varying an gles, while the intervening spaces aremade of spots of darker bark, smaller and narrower chips running down tothose of little more than line width, and disposed at many angles andfilled between with spots of granular wood material. When a surface ofthis nature is stained and varnished the hard flat surfaces of thelarger pounded chips absorb less stain than the bark Or the open grainof other pieces and provide high lights which in the resultant patternpresent a very attractive mosaic. The small voids at the surface alsoshow up and produce a product which in a beam, for example, rivals inattractive appearance the so called pecky-cypress beams valued for theirdecorative effect in tropical h'omes. Upon the other hand, if we paintover a board of this sort with, for example, a light blue paint and wipethe surface with a rag while the paint is still wet, the paint wipesoil? of the hard flat surfaces of the larger chips and most of thosesurfaces flush therewith, but clings in the open grain surfaces of theother particles and in the interstices between particles, outlining apattern distinctive of the particular disposition of the particles inthat piece. The pattern produced would differ with every piece produced.No two would ever be alike. However, in order to give as good an idea aspossible of the nature of the surface produced, I have photographicallyillustrated in the accompanying drawing, made a part hereof, a.representation of a block made as above described, enlarged to aboutdouble size.

With a board having such'a surface it is possible to secure a multitudeof polychrome effects of the nature of those which a painter hasheretofore secured in the finishing of rough cast plaster walls. Andeven when no pigment is employed and only a transparent coating, such asvarnish, is applied to the natural, multl-shaded surface of the product,the result is of such beauty as to render it possible to use such aboard in the direct finishing of libraries, dens, restaurants and otherplaces where ordinarily high priced, beautifully grained woods wouldfind a place.

I do not limit myself to any particular binder. However I have foundurea formaldehyde to be valuable in this relation. For example, I maytake of the comminuted hammered wood waste two pounds and mix with thisa binder consisting of two to four ounces (preferably three ounces), of

urea formaldehyde plastic glue and one-fourth to one-half pound of ryeor wheat flour as an extender. To this I add one to two pounds(preferably about 1 and three-quarters pounds) of water. The whole ismixed to a damp mass and then molded to the desired form. This moldingmay take place as a simple step by step pressing operation or in acontinuous operation in any suitable machine, either with or without theapplication of heat. If the urea formaldehyde glue be increased incontent the hardness and waterproof qualities of the product will beincreased.

I contemplate employing this basic product (to wit, the product securedby passing hog fuel through a hammer mill to secure a. heterogeneousproduct of hard wood, bark, twigs, etc. ranging from wood meal to fairlylarge fiat sided chips), in conjunction with other types of binders,such as plaster of Paris, gypsum, etc., and in connection with any type,of binder I contemplate the employment of any desired chemicals. Forexample, para-formaldehyde makes a good preservative resistant to theravages of insects. I may add animal glue, wh'ere deemed desirable, andsmall amounts of acids, such as oxalic acid. I wish to cover the use ofurea formaldehyde and grain flour in any proportions.

It will be observed that the base product which I employ diifers veryradically from the base products employed in most wall boards in that itis composed, in the main, of particles so large, so hard and soheterogeneous as to size and shape as to be wholly unsuited for thefelting commonly resorted to in the manufacture of wall board and whichresults in the production of products very weak in one direction, towit, laterally. That is to say, pressure applied through the thicknessesof many of these boards easily breaks them.

However, I wish to emphasize the fact that this invention amounts toradically-more than merely varying the size of comminuted wood. Forexample, in my co-pending application, Ser. No. 491,546, filed June 19,1943, now Patent No. 2,441,169, May 11, 1948, I disclose a wall boardformed by compressing relatively coarse woody particles (shavings) and abinder. However, there is no comparison between. the ultimate products.The compressed shavings product is very characterless in appearance ascompared with the product of this invention. This is due to the factthat it is of such uniform color asto yield no contrasts and very littledesign. The product of the present invention, upon the other hand,yields a terrazzo like effect, because of the presence of woods of manydiiferent kinds,

woods from many different parts of the log, particles of bark and thehardening and burnishing eflect upon the chips of larger size. arisingfrom the pounding and rubbing action of the hammer mill, thereon. In thedrawing some of the large flat faced chips are indicated at 5, theirwhisierfd edges at 8 and the dark splotehes of bark at It is to beunderstood that the invention is not limited to the precise constructionset forth, but

that it includes within its purview whatever changes fairly come withineither the terms or the spirit of the appended claims.

1. A wood product composed of a binder-and a mass of comminuted woodresulting when ho fuel is subjected to the action of a hammer mill. toproduce a multiplicity of relatively large flat- Having described myinvention, what I claim tened chips having their faces burnished by therubbing action of a hammer mill togther witlf a mass of smaller woodparticles including those from the bark and leaves of the hog fuel.

2. The hereindescribed method of making artificial wood shapes whichconsists of subjecting hog fuel' with its contained bark, twigs andleaves to a comminuting and pounding and rubbing action tov reduce it toa mass containing. per

ticles ranging from the granular to chips of considerable length andwidth, the pounding and rubbing action flattening and burnlshing saidchips and compressing their fibres to leave protruding whisker-likeedges therealong, mixing said particles in a heterogeneous mass with awater repellent, adhesive binder, and pressing the whole into thedesired shape.

3. An artificial wood shape composed of an adhesive binder and-a mass ofwood particles ranging in size from wood meal to chip-like particles,

said particles being those produced, when hot fuel including the barkand twigs, is'comminuted in a hammer mill to yield a product in which atleast some of the chips range to three quarters of an inch in length andthree eighths oi an inch in width and wherein said chips have beenflattened and hardened by the hammering action of said mill and, whereinsome of said chips have whisker-like fibres along their edges, whereinthe said binder is composed of the following ingredients' mixed witheach other and with the wood particlesin the following proportions, to

wit:

Comminuted wood products pounds 2 Urea formaldehydeounces 2 to 4 Flourp0unds V4 to V2 CHARLES ROMAN.

REEERENcEs clTEn I: The following references are of record in the file01' this patent:

May 1938.

